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Re: VLF question

 



On Tuesday, February 11, 2025 at 09:20:29 PM PST, Gedas via groups.io <w8bya@...> wrote:


I have been meaning to try an earth probe antenna here for over a year. I wanted to make one about 500' long with each end terminated by 8' copper coated ground rods.

When you think about it, in practice, it sort of resembles (to me) a weird folded dipole of sorts.? A somewhat folded dipole where the "top dipole wire" is running along on the ground surface while the bottom dipole is a complex form comprised of the two copper rods driven in the ground and whatever conductivity exists between them via the soil. I might be wrong but my gut tells me that the top dipole, the wire laying on the ground contributes quite a bit to the antennas characteristics.
Gedas, W8BYA EN70JT
Light travels faster than sound.....
This is why some people appear bright until you hear them speak.
On 2/11/2025 11:24 PM, Facility 406 wrote:

On 2/11/2025 11:55, Everett N4CY via groups.io wrote:
What would happen if you put two ground rods in the ground, spaced 25' to 50' apart and use an amplifier?

I'd have to dig out some old books, but I think the Germans were doing that, minus the amp at the time, in the 1860's.? I seem to recall a section in one of my radio books from around 1906 having a decent writeup on it.? It wasn't called radio yet, but was known as wireless at the time, and detected intentional signals, but it was the beginning.

For several decades, probes with amplifiers were the go-to.? Probes ranged from screwdrivers stuck in the dirt in gardens, to 1m rods tens of meters apart.? Several years ago, I asked about two probes, one about 200' deep, the other, about 500', 1/2 mile apart.? No response.? I no longer have access to both of those probes.? I also had the idea of a 1/2 mile loop, and up to a dozen turns a half mile around each.? I may still play with that.

Here is some probe info:



If you can find references to the old ELF/ULF forum that was on Yahoo, it was almost entirely discussing probes.

This one may parallel it:

/g/VLF

If not, people at the above forum may have info.

Kurt







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